/**
 * The MIT License (MIT)
 *
 * Copyright (c) 2017-2023 Ta4j Organization & respective
 * authors (see AUTHORS)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
package org.ta4j.core.indicators.volume;

import org.ta4j.core.BarSeries;
import org.ta4j.core.indicators.CachedIndicator;
import org.ta4j.core.num.Num;

/**
 * Rate of change of volume (ROCVIndicator) indicator (also called "Momentum of
 * Volume").
 *
 * <p>
 * The ROCVIndicator calculation compares the current volume with the volume "n"
 * periods ago.
 */
public class ROCVIndicator extends CachedIndicator<Num> {

    private final int barCount;
    private final Num hundred;

    /**
     * Constructor.
     *
     * @param series   the bar series
     * @param barCount the time frame
     */
    public ROCVIndicator(BarSeries series, int barCount) {
        super(series);
        this.barCount = barCount;
        this.hundred = hundred();
    }

    @Override
    protected Num calculate(int index) {
        int nIndex = Math.max(index - barCount, 0);
        Num nPeriodsAgoValue = getBarSeries().getBar(nIndex).getVolume();
        Num currentValue = getBarSeries().getBar(index).getVolume();
        return currentValue.minus(nPeriodsAgoValue).dividedBy(nPeriodsAgoValue).multipliedBy(hundred);
    }

    @Override
    public int getUnstableBars() {
        return barCount;
    }

    @Override
    public String toString() {
        return getClass().getSimpleName() + " barCount: " + barCount;
    }
}
